1. Field of the Invention
This invention relates in general to an apparatus for mounting an outboard motor on the transom of a boat so that the motor can be raised and lowered relative to the transom. More specifically, the present invention utilizes angular motion from the outboard motor's tilt and trim apparatus to obtain the desired movement.
2. Prior Art
For maximum efficiency of operation, an outboard motor should be mounted on the transom of a boat such that the cavitation plate of the motor runs across the water surface once the boat has reached a planing condition. Depending on variables such as boat size, weight, load, hull configuration, and horsepower, it is desirable to have the capability to raise and lower the motor vertically as conditions dictate to achieve maximum thrust, maximum speed, minimum drag, and/or maximum fuel economy. Outboard motor manufacturers have attempted to increase the versatility of their motors by offering a motor tilt and trim apparatus that provides for angular movement of the motor, and therefore the propeller relative to the transom bracket that secures the motor to the transom. A typical hydraulic tilt-trim system is described in Hundertmark U.S. Pat. No. 4,391,592. The trim portion of the movement in general provides 15 degree of movement and is functional when the boat is operating at any speed or load. The tilt feature of the movement extends generally 40-60 degrees past the trim range and is functional only at slow speed, low load, and when the motor is not running. The tilt function is primarily intended for beaching of the boat, operating at slow speeds in shallow water, and raising the motor out of the water for trailering and when the boat is otherwise not in use.
A typical outboard motor mounting apparatus of Cook U.S. Pat. No. 4,482,330 provides for mounting the outboard motor on the transom of a boat so that the motor can be raised and lowered on the transom. One version of the apparatus utilizes an electric pump and hydraulic cylinder to obtain the force necessary to move the motor vertically. In combination with the outboard motor's tilt and trim features, many combinations of vertical and angular positioning of the outboard motor are possible to allow; the operator a variety of choices of motor trim/tilt, and vertical motor positioning, as conditions and objective warrant. The outboard mounting apparatus of Cook U.S. Pat. No. 4,482,330 is equipped with a transom bracket and motor bracket. The hydraulic action results in movement of the motor bracket relative to the transom bracket thereby providing the means for the vertical movement of the motor relative to the transom. The force required for this movement is provided by a hydraulic actuating cylinder and reversible hydraulic pump driven by an electric motor through a switching circuit powered by the motor's automotive type battery. Needless to say, the motive force required to operate the system entails expense, added weight, complexity, and additional electrical draw from the battery. These factors make the system less desirable to the average outboard motor boat owner.
Similar systems are being produced that provide for adjustment of the motor bracket manually. Typically, this entails a set-up similar to the system previously described however the activating cylinder, hydraulic pump, electric motor, and switching circuit are eliminated. The motive force is generally provided by a manually operated threaded bolt adjusting mechanism. Advantages of this system include: A substantial cost savings over the hydraulic system, a less complex system and therefore less likelihood for failure, less weight, and no current draw from the electrical system. Disadvantages of these systems include: less flexibility in the motor positioning since no adjustment can be made while the boat is underway, and less convenience in changing the motor position since the changes are made manually. Generally, the adjustment must be made from a position outside of the boat. An adjustable outboard transom device exists that enables the operator to adjust the motor vertically on a typical transom jack from inside the boat with more rapid height adjustments than is possible with the conventional threaded bolt adjusting mechanisms. This is detailed in Goodman U.S. Pat. No. 4,624,438. This device however requires manual mechanical input from the operator and cannot feasibly be operated while the boat is being operated.
No device is known, however, that combines the cost savings, weight reduction, and simplicity of the manual outboard motor mounting apparatus with additional attributes of the hydraulic outboard motor mounting apparatus.